The term 'prefix with hertz' refers to a set of four prefixes used in the International System of Units (SI) to denote powers of 10. The prefixes are kilo (k), mega (M), giga (G), and tera (T). Kilo stands for 1000, mega stands for 1 million, giga stands for 1 billion, and tera stands for 1 trillion. These prefixes are often used in combination with the unit hertz (Hz), which is a measure of frequency. For example, kilohertz (kHz) is equal to 1000 Hz, megahertz (MHz) is equal to 1 million Hz, gigahertz (GHz) is equal to 1 billion Hz, and terahertz (THz) is equal to 1 trillion Hz.